The answer you are looking for is n = -30.
This can be found by first distibuting 4 into the parenthesis (5 - 2n). This will give you 20 - 8n. Next, you add 20 to both sides, which gives you 7n - 8n = 30. Then, you'd combine like terms (7n and -8n), to get -1n. Finally, you divide bith sides by -1. This gives you a final answer of n = -30.
I hope this helps!